The present invention relates to a sample delivering method for use in an automatic chemical analysis, particularly in a multi-channel multi-item automatic chemical analyzer.
Presently, most multi-item chemical analyzers can perform many different analyses for test-items by using a plurality of channels arranged to improve the test-item processing ability per unit hour, i.e., the through-put. However, when using these multi-channel multi-item automatic chemical analyzers, it is very rare for all test-items to be performed for each sample. Therefore, in the actual analysis many reaction tubes are not used.
FIG. 1 is a schematic view showing one embodiment of a conventional multi-channel automatic chemical analyzer. In FIG. 1, a plurality of reaction tubes 2 are arranged on a turntable 1 which rotates in a clockwise direction. The reaction tubes 2 are arranged along four channel reaction lines concentrically with respect to a center of the turntable 1. The respective reaction lines are denoted by numerals 3, 4, 5, 6 from outer to inner lines. The first three of these correspond to test-items .alpha., .beta., .gamma., respectively, while the last correspond to an undecided, i.e., variable, test. A plurality of sample tubes 7 are arranged along a sample line situated beside the turntable 1 and can move leftward as shown by an arrow. The sample tubes 7 are moved one step at a time in synchronism with the turntable 1. Starting from the tube situated at the delivering position X the sample tubes have been labeled A, B, C, D, respectively, and the corresponding reaction tube series are denoted by a, b, c, d, respectively. Therefore, relevant sample tubes A, B, C, D correspond to relevant reaction tube series a, b, c, d at the delivering position X. Moreover, a suitable delivering mechanism is arranged at the delivering position X to supply a sample contained in the sample tube into the reaction tubes. In this embodiment, the delivering mechanism functions to supply the sample at the delivering position X to first, second and third reaction lines 3, 4 and 5. It should be noted that the sample is not supplied to the fourth reaction line 6 by this delivering mechanism because the test-item for the reaction line 6 is undecided.
In the conventional multi-channel automatic chemical analyzer mentioned above, the sample is selectively delivered into the reaction tubes in accordance with test-items to be performed for the relevant sample. Now, for illustration it is assumed that the test-item .alpha. is to be performed for the samples A, B, C and D, the test-item .beta. is to be effected for the samples A and C, and the test-item .gamma. is to be effected for the samples B and C. The sample A then is delivered into the reaction lines 3 and 4 of the reaction tube series a, and then the sample B is delivered into the reaction lines 3 and 5 of the reaction tube series b after shifting the sample tube 7 and the turntable 1 by one step. Similarly the sample C is delivered into the reaction lines 3, 5 of the reaction tube series c, and the sample D is delivered into the reaction line 3 of the reaction tube series. Therefore if the step period is assumed to be T, the processing efficiency is 4/T.
However, in the conventional delivering method mentioned above, no analysis is performed for the reaction tubes in the reaction line 6 and thus the reaction tubes remain vacant. Moreover, even if a new test-item is selected for the reaction line 6, only very rarely will all the test-items be performed for each sample, and thus the drawback remains that many vacant reaction tubes which are not used for the analysis remain on the turntable.